Refrigeration



Nov. 16, 1937. H. M. ULLSTRAND 2,099,941

A REFRIGERATION Filed July 9, 1936 INVENTOR.

W ATTORNEY.

Patented Nov. 16, 1937 UNITED STATES PATENT ()FFICE REFRIGERATION Hugo M. Ullstrand, Evansville, Ind., assignor to Serve], Inc., New York, N. Y., a corporation of Delaware My invention relates to a method of and apparatus for producing refrigeration in connection with internal combustion engines which are eitherstationary or employed for driving or propelling automobiles, motor boats, motor vehicles,

or the like.

It has been proposed to produce refrigeration in connection with internal combustion engines wherein the expansion of fluid fuel is utilized to produce cold, and the fuel is subsequently introduced into the engine.

It is an object of my invention to provide an improved system for producing refrigeration in connection with internal combustion engines whereby a greater amount of useful cold is produced. I accomplish this by supplying only a portion of the air to the region of lower pressure in which the expansion of fuel takes place, and subsequently supplying additional air to the gaseous mixture which is formed in the region of lower pressure before such mixture is introduced into the engine.

My invention, together with the above and other objects and advantages thereof, will be more fully understood upon reference to the following description and the accompanying drawing forming a partof this specification, and of which Fig. 1 is a diagrammatic illustration of an embodiment of my invention for an internal combustion engine shown in connection with a refrigeration system; and Fig. 2 is a modification of the embodiment shown in Fig. 1.

Referring to Fig. 1 of the drawing cylinder block IU of an internal combustion engine such as, for example, for a motor vehicle, is provided with an intake manifold M. The combustible mixture of air and fuel flows to the suction inlet of the manifold M through a conduit I2, and is delivered in the usual manner to the cylinders. A well insulated vaporization chamber or conduit I4 is arranged between a carburetor l5 and duct I6 and forms, with the connecting member or conduit l2, part of the gas passage leading to the intake manifold M. The chamber I 4 serves for the production of cold 'and within it is disposed a coil II connected by conduits I8 and I9 to a second coil 20 which is located within the compartment of a refrigerator cabinet 2|. The coils 50 I! and 20 and connecting conduits l8 and I9 form a closed system which is filled with a, fluid that absorbs heat from the refrigerator cabinet 2| and transfers this heat to the chamber M- where the heat produces evaporation of the fuel 55 for the engine. This fluid, which may be termed an auxiliary fluid, may evaporate in the coil 20 and condense in the coil I1.

' Air may be supplied to the carburetor l5 through conduit 22, tubes 23 which are arranged within the duct I6 and open at both ends, and conduit 24'which is open to the atmosphere. The tubes 23 and duct I6 form a heat exchange device 25. Between conduits l2 and 24 is connected an air by-pass conduit 26, and in the conduit l2 between the by-pass conduit 26 and intake manifold II is connected a compressor 21 which may be termed a supercharger. The compressor 21 may be driven, for example, by the internal combustion engine Ill. The compressor 21 withdraws the gaseous mixture from the duct I6 and also draws air directly from the atmosphere through by-pass conduit 26 which mixes with the gaseous mix ture and increases the proportion of air in the latter. Control valves 28 and 29 are arranged in the conduits 24 and 26, respectively, and are connected by levers 30' and 3| to a common control member 32.

During normal operation of the engine, atmospheric air enters the conduit 24 and flows through the tubes 23 and conduit 22 to the carburetor IS.

The liquid fuel, which is conducted from a suitable source of supply (not shown) and may consist of liquid benzene or gasoline or a mixture therepf, for example, is atomized in the carburetor I5 and passes in a finely divided state into the vaporization chamber I4 together with the air supplied from the atmosphere.

The pressure within the chamber I4 is below that of atmosphere because of the suction produced by the compressor 21, and this reduced pressure causes evaporation of the fluid particles. Due to this evaporation of the fluid particles heat is taken up from the surroun'dings, and, since the vaporization chamber I4 is well insulated, this heat can only be withdrawn from the coil IT. The cold produced in the vaporization chamber I 4 is transferred by the fluid in the coil IT to the part to be cooled, such as the refrigerator cabinet 2|, as described above.

The air in the chamber 4, which is saturated with fuel vapor, flows through the duct I6 and cools the incoming air flowing through the tubes 23 of the heat exchange device 25. From the duct I6 the air saturated with fuel vapor flows into the duct I2 and mixes with additional air drawn directly from the atmosphere through conduit 24 and the by-pass conduit 26. The combustible mixture in the conduit I2 flows into the compressor 21 from which it is discharged at an increased pressure into the intake manifold ll pass conduit 26, the amount of useful refrigeration produced in the chamber I4 is greatly increased. Whereas approximately fifteen pounds of air is required per pound of gasoline for the operation of theinternal combustion engine, only slightly more than one pound of air is theoretically required to evaporate one pound of gasoline at 22 F. When only a portion of the air required for the combustible mixture is supplied to the carburetor l5, lower refrigeration temperatures are obtained in the chamber it. With a smaller quantity of air flowing through the tubes 23, the load on the heat exchange device 25 is less whereby the latter may be reduced in size. If it is assumed that the efliciency of the heat exchange device 25 is about 70 per cent, the amount of useful refrigeration obtained in a system of the character described above is increased more than 100 per cent over similar systems in which all of the air is supplied to the carburetor.

Fig. 2 illustrates a modification of the embodiment shown in Fig. 1 in which similar parts are indicated by the same reference numerals. This modification differs from the embodiment described above in that the vaporization or cooling chamber I4 is located directly in a compartment 39 to be cooled and is provided with flns 33 to increase the amount of heat transfer surface. In order to increase the amount of useful refrigeration obtained, liquid fuel flowing to the carburetor I is pre-cooled by flowing in contact with air which has been cooled in the tubes 23 of the heat exchange device 25. This may be accomplished by conducting fuel from a. source of supply (not shown) through conduit 34 to the carburetor l5. The conduit 34 is provided with an enlarged chamber 35 which is connected at opposite ends by means of conduits 36 and 31 with the duct I6 and header 38 at the end of the heat exchange device 25 adjacent the carburetor I 5.

The operation of the embodiment shown in Fig. 2 is substantially the same as that described above in connection witlr the embodiment shown in Fig. 1 and differs therefrom inthat heat is transferred directly from the compartment 39 to the vaporization or cooling chamber M. In addition, the liquid fuel flowing to the carburetor I5 is pre-cooled in the chamber 35 by cool air which flows through conduit 31 into the cham- 60 ber 35 and from the latter through conduit 36 into the duct l6. By pre-cooling the liquid fuel in chamber 35,' additional cooling in the vaporization chamber I4 is obtained.

Although I have shown and described several embodiments of my invention, it will be apparent to those skilled in the art that various modifications and changes may be made without departing from the spirit and scope of my invention.

What is claimed is: 1. A method of refrigeration with the aid of an internal combustion engine which consists in producing a region of pressure lower than that obtainable by the suction action of said engine.

by heat transfer tosaid mixture, adding additional air to said gaseous mixture after such heat transfer to form a suitable combustible mixture, increasing the pressure of said combustible mixture, and introducing said combustible mixture at an increased pressure into said engine.

2. Refrigeration apparatus including an internal combustion engine, a cooling membenmeans for conducting air to said cooling member including a heat exchanger, means for conducting liquid fuel to said cooling member including a carburetor, and means including said heat exchanger and a compressor for conducting an air-gas mixture from said cooling member to said engine and for introducing additional air to said mixture before it enters said engine.

3. Refrigeration apparatus including an internal combustion engine, a cooling member, means for conducting air and volatile liquid fuel to said cooling member, and structure for conducting an air-gas mixture from said cooling member to said engine, said structure including means for adding additional air to said mixture and for introducing said mixture into said engine at an increased pressure.

4. A method of refrigeration with the aid of an internal combustion engine operating on liquid fuel and air, which comprises admitting said liquid fuel to a region of lower pressure and supplying heat by conduction from a body to be cooled external to the path of flow of fluids supplied to said engine to cause vaporization of the fuel, introducing a portion of the air to said region to form a mixture of the air and the vaporized fuel, cooling air before introduction into said region by heat transfer to said mixture, adding additional air to said mixture after such heat transfer to form a suitable combustible mixture, and introducing said combustible mixture into said engine.

5. A method of refrigeration with the aid of an internal combustion engine operating on liquid fuel and air, which comprises admitting said liquid fuel to a region of lower pressure and supplying heat by conduction from a body to be cooled external to the path of flow of fluids supplied to said engine to cause vaporization of the fuel, introducing a portion of the air to said region to form a mixture of the air and the vaporized fuel, cooling the air before introduction into said region by heat transfer to said mixture, cooling liquid fuel before introduction into said region by heat transfer to a portion of the pre-cooled' air, mixing said portion of the air with said gaseous mixture, thereafter adding additional air to said gaseous mixture to form a suitable combustible mixture, and introducing said combustible mixture into said engine.

HUGO M. ULLSTRAND. 

